Method of and apparatus for the manufacture of sheet glass



DEC. 1, PI

METHOD OF AND APPARATUS FOR THE MANUFACTURE OF SHEET GLASS Filed June 18, 1927 3 Sheets-Sheet l Dec. 1, 1931. SPlNASSE 7 1,834,656

METHOD OF AND APPARATUS FOR-THE MANUFACTURE OF SHEET GLASS Filed June 18, 1927 5 Sheets-Sheet 2 Dec. 1, 1931. A. E. SPINASSE METHOD OF AND APPARATUS FOR THE MANUFACTURE OF SHEET GLASS Filed June 18, 1927 3 Sheets-Sheet 3 Patented Dec. 1, 1931 UNITED STATES PATENT OFFICE ARTHUR ESPINASSE, F MOUNT VERNON, OHIO METHOD OF AND APPARATUS FOR THE MANUFACTURE O1! SHEET GLASS Application filed June 18,

The present invention relates to improvements in method of and apparatus for drawing glass, and has for an object to provide an improved method and apparatus forthe drawing of glass sheets, in which the border and edge portions of the sheet will be drawn of a more uniform character with the body 7 portion of the sheet to avoid the present large waste of glass in such border portions, which according to existing methods and apparatus are drawn abnormally thick.

Another object of the invention is to provide an improved method and apparatus for drawing sheet glass, wherein checks and cracks in the border portions are avoided, in

which a more effective longitudinal stretching action is had in the border portions to prevent the collapse or narrowing of the sheet, and in which a better temper is imparted to such border portions.

A further object of the invention is to provide an improved method of drawing glass sheets, which involves'the confining of the border portions of the sheet, promptly after formation and drawing, in casings which retain the heat of the border portions, afl'ording a better temper, more uniform thick-- ness in the border portion, and better longitudinal tension to maintain the uniform width of the sheet.

With the foregoing and other objects in View, the invention will be more fully described hereinafter, and will be more particularly pointed out in theclaims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure 1 is a vertical sectional view taken through a portion of a tank furnace showing the improved apparatus partly in section and partly in elevation.

Figure 2 is also a vertical section taken atsubstantially right angles to Figure 1 and on the line 22 in Figure 1.

Figure 3 is an enlarged horizontal section taken on the line 3-3 in Figure 2.

Figure 4 is a perspective view of one of the heat retaining casings and edge forming members.

1927. Serial No. 199,815.

Figure 5 is a similar view showing a slight modification, and 3 Figure 6 is a section, taken on a smaller .scale, corresponding approximately to Figure 3 but showing the two devices at opposite edges of the sheet.

Referring more particularly to the drawings, 7 designates a conventional form of tank furnace, and 8 represents a shoulder receptacle or pot communicating with the furnace 7 and for holding a bath of molten glass received from the furnace from which to draw the sheet of glass indicated at 9. The usual meniscus, wedge or blank is shown at 10 where the lass sheet issues from the upper surface .of the bath of glass in the receptacle 8 at the drawing zone. -Thereceptacle 8 is formed with side walls 11. and outer wall at 13 is placed about the walls to avoid the too" rapid dissipation of the heat.

Below the receptacle or pot 8 are disposed a number of independent heating chambers. In the embodiment shown in the drawings, three such' chambers are provided, namely, a central chamber 14 located directly beneath the base or meniscus of the glass sheet and extendin in line with said sheet; two lateral heating c ambers 15 and 16 which are separated from the central chamber 14 by the partitions 17 and 18.

As shown in Figure 2, the end walls 19 of the chambers are each provided with ports or openings 20, preferably tapering in longitudinal section. Arranged before these openings are the burner nozzles 21 having therein the controlling valves 22. The walls 19 terminate short of the bottom of the pot or receptacle 8 and in the recesses 23 thus formed are placed the dampers 24, preferably of slightly less width and height than the corresponding diameters of the recesses 23.

These dampers 24 are shiftable in and out in the recesses 23 to control the outlet of the heat from the chambers. As also shown in Figure 2, the side walls- 11 of the pot or receptacle 8 are provided at an appropriate elevation with the internal through the insulation 13 to admit a fluid or chambers or recesses 25 open outwardly temperature controlling medium therein introduced through the pipe 26 under the control of the valve 27.

As shown in Figure 1 housings extend above the pot or receptacle 8. One of these housings includes the outer wall 28, the end walls 29 and roof 30. ith the shield 31, these walls form a closed chamber into which a heat affecting medium is introduced under control through the pipe 32. The other housing is formed in part by the furnace wall, by the end walls 33, roof 34 and the other shield 35. In like manner a heat affecting medium is introduced into this second closed housing under control through the pipe 36. The roof 34 is provided adjacent the furnace wall with an opening 37 into which extends an ad j ustable damper 38 in position to regulate the heat issuing from the melting furnace through the passage or opening 39.

The shields 31 and 35 extend in parallel and spaced relation at opposite sides of thedrawing zone and rest upon the sides of the pot or receptacle 8 or supported in any appropriate manner. Above the shields are the supporting members 40 and 41 upon which rest the side walls 42 and 43 of the vertical annealing leer up through which passes the sheet of glass 9 being drawn. The drawing rolls are indicated generally at 44 and the usual floor within the leer at 45.

Coolers are shown at 46 and 47 within the shields 31 and 35. These coolers are of well known form and are supported in known manner by the pipes 48 and 49, shown more particularly in Figure 3.

The border portions of the glass sheet are shown as being drawn upwardly through edge forming or shaping members. These members, according to the embodiment of the invention, shown in Figure 4, are carried by plates 50 and consist of the lips orwalls 51, 52 and 53. The side walls 51, 52 converge upwardly and also converge outwardly with respect to the glass sheet. The end Wall 53 converges upwardly toward the glass sheet. The result is the formation of a slot wider at its base than at its upper portion and wider at its inner open portion than at the closed end 53. The slot progressively narrows from its base to its upper portion and from its open end to its closed end. The border portion of the glass sheet is drawn upwardly through this slot, as clearly shown in Figures 2 and 3, whereby a characteristic form is imparted to the edge and border portion, and this characteristic form, as shown in Figure 3, fora great majority of the border portion and edge is uniform with the body portion of the sheet.

Associatedwith the edge forming members are heat retaining casings for enveloping the border portions and edges of the glass sheet after emerging from such members. One form of heat retaining casing is also shown in Figure 4, in which 54 and 55 designate the side walls of the casing and 56 the outer end wall thereof. These walls at their base may be in one piece with, or attached in any manner to the plate 50 or to the edge and border forming members. At their upper ends the side walls 54 and 55 are provided with convergent parts 57 and 58 and the rear wall is shaped to accord with this formation. A slot 59 is formed between the convergent upper roof portions 57- and 58 for the free passage of the border portions of the glass sheet 9.

The side walls 54 and 55 at appropriate points .are formed with the windows or open ings 60 arranged to be masked by the doors 61 hinged or otherwise mounted, as indicated at 62 upon the outside or other portions of the walls.

The outer wall 56 is also provided, preferably at its lower portion with anopening adapted to be closed by the doors 63 and 64 hinged or otherwise mounted on the side walls or other portions,as indicated in Figure 3.

The casings may be supported by the brackets 65 secured thereto as by the bolts or other fastenings 66 and supported for horizontal swinging adjustment on the .bolts 67 carried by the adjusting arms 68. These arms 68 are provided with the horizontal elongated slots 69 intercepting the vertically elongated slots 70in the standards 71. A bolt or other fastening 72 is arranged to pass through the registering portions of the two slots and to bind the arm 68 in adjusted position upon the standard. The slots admit of horizontal and vertical sliding adjustments and also of a pivotal adjustment in a vertical plane.

In Figures 1 and 2 the preferred position of the casing is shown in which the plate 50 at the lower end is supported in spaced rela tion above the surface of thebath of glass and in spaced relation above the side walls 11 of the pot or receptacle 8. Dampers 7 3 upon the walls of the pot or receptacle 8 are adjustable to regulate the amount of escaping heat passing beneath the plates 50. Referring now to Figure 5 a slightly modi fied form of casing and adjacent parts is shown in which the plate 50 is dispensed with,

leaving merely the upwardly extending Walls provide the cooling medium to the recesses 25 for thepurpose of intensifying the adherence of the glass to the anchorage points 75, are flanked by heating pipes 76 and 77 for introducing hot gases to the recesses 7 S and 79 in the receptacle wall to minimize as much as possible the adherence of the glass at the opposite sides of the anchorage, whereby to restrict and confine the anchorage as much as possible within the small confines of the plane of the base of the sheet to be drawn.

In operation, the glass sheet 9 is drawn in the usual way from the bath of glass in the receptacle 8, the'border portions passing through the edge forming members, which have been pre-heated preferably to red heat to secure an adherence of the glass thereto. The intermediate or body portion of the sheet 9 is left free both of the shaping members and the heat retaining casing as the difliculty with present methodslies in the drawing of the border portions and edges which have a tendency to cool more rapidly than the remainder of the sheet, resulting in the formation of thick and'brittle edges subject to checks and cracks when passing through the drawing apparatus and which thickened edges are required to be cut away and constitutes simply cullet waste. Moreover, fur-, ther difficulty is encountered in the cutting away of such edges due to the tendency of the glass to explode with injurious effect to persons and to the adjacent portion of the.

sheet.

The too-rapidly cooled edges interfere with the proper sliding action of the glass through the shaping lips and in general interfere with the stretching of the border portions above the shaping members.

' In accordance with the present invention the edge forming devices, which may be made of any desired material such as metal or burned clay, and preheated as above exlained, are positioned in fixed position adjacent above the surface of the bath to thereby retain said heated condition and also to engage the upper portion of the meniscus or blank 10 of the glass sheet and to subject the drawn glass to an adhering dragging action throughthe lips 51, 52 and 53, which have a forming and shaping efi'ect, partially reducing the thickness or mass of the wedge. The hot shaping member also acts as an anchorage for maintaining the desired width of the sheet. The width or general proportions of the upper narrower portions of the slot in the -lips is, however, greater than the final thickness of the sheet of glass 9 resulting in the formation of a secondary meniscus or blank 80. This secondary meniscus emerges from the lips into the lower portion of the heat retaining casing without being subject to any severe external cooling. The border and edge portions of the sheet are drawn upwardly through tne heat retaining casing which confines and retains the heat of the drawn glass, preventing its rapid dissipation and the presence of this heat reacts on the drawn border portions and edges to prevent a too rapid cooling of the border portions. The border portion and edges within the confined length of the casings are thus preserved in a condition more favorable to the stretching action which takes place between the drawing rolls 44 and the lips of the edge forming members between which there is an adherent slippage of the glass. By opening the doors 63 and 64 of the heat retaining casing to a desired degree, inspection of the condition of the border portions and sheet edges may be had, and also a regulation of the temperature within the casing maintained. The heat would thus be permitted to escape from the opening and cooling air would be admitted.

A further regulation is had by means of the doors 61 in the side walls which are shown intermediate the height of the casings. By opening these doors through a proper angular distance a nice regulation may also be had, as the ascending heat in the casing is thus permitted to flow out in regulated masses. The sloping upper roof portions 57 and 58 of the casings tend to confine the ascending heat to prevent its being too rapidly dissipated.

In the case of Figure 5 the heat insulating lining 74 will still further tend to hold the sixteen to thirty inches and the width fromthree to fourinches depending uponthe thickness of the glass which is to be manufactured. The plates 50 preventthe dissipation of heat from the bath of molten glass in the recepta cle 8, and thus avoid the formation of cooler areas of glass. The coolers 46 and 47 extend only across the body portion of the glass and not across the border portions and edges. As shown in Figure 1, the adjustable dampers 7 3 provide for regulating the temperature of the plates 50 and edge forming members. By drawing these dampers 73 outwardly more air is admitted to and beneath the plates 50, or allows greater dissipation of heat from the members and thus the lowering of the temperature thereof toeifect greater adhesion of the glass thereto. The doors 63 and.

64 in the lower portions of the casings also have a like effect from above upon the edge forming members, and a more direct effect upon the upwardly extending lips 51, 52 and 53, so that a conjoint adjusting of the damp ers 73 and the doors 63 and 64 will effect a nice regulation of the temperature of all parts of the plate 51 and the forming lips.

cooperates with the temperature regulation of the edge forming members to produce and maintain the border portions in a properly tempered and stretchable condition.

The plate 50 assists in preventing the formation of cooler areas of glass adjacent the source of the drawn edge of the sheet.

The effect of the central heating chamber 14 below the glass pot or receptacle 8 is positioned to have a direct effect upon the column of glass in the receptacle lining thereabove up to and including the meniscus or blank 10, whereby the heat regulation in the central heating chamber 14 directly affects the condition of the glass in themeniscus or blank 10, and consequently the regulation of heat in the central chamber 14 bears a direct relation to the temperature condition of the border and edge forming members. The regulation of the temperature in the chamber 14 and of the edge forming members and plates 50 is dependent upon the nature of the glass and other known conditions, and these temperatures must be relatively varied from time to time within the skill of the worker. Moreover, the lateral heating chambers 15 and 16 may be independently controlled as to temperature and these chambers control and regulate the temperature condition of the bath at opposite sides of the drawing zone and the meniscus or blank 10. By a conjoint regulation of these various temperatures a proper homogeneity in the glass bath at the drawing zone adjacent the meniscus or blank 10 may be obtained.

WVhile, therefore, the glass at the sides of the drawing zone are kept at a slightly higher temperature than at the drawing zone itself, devitrification of the glass in the drawing chamber is substantially entirely eliminated.

The bracket and supporting device for the heat retaining casings enables the devices to be raised and lowered or moved in and out.

This also applies to the temperature condition of the plate 50 and the edge forming members.

The glass adhering. to the hot walls of the shaping member or lips is not chilled thereby, adheres to the lips and issues therefrom into the heat retaining casing in a more workable and soft condition with the result that a gradual and more effective stretching of the border portions of the sheet is had,

thinner edges and border portions more smooth and of better texture and temper are produced, and edges and border portions more in uniformity with the body portion of the sheet result. I

Due to the construction of the shaping lips, a constant adherent contact of the rising meniscus is secured, irrespective of its variation in thickness. Should the meniscus decrease in thickness because of an increase in temperature in the glass, or because of a change in the working condition of the glass, or when drawing thinner sheet glass, the resulting thinner meniscus will nevertheless still engage the shaping lips, but at the narrower outer closed portion thereof. When the meniscus increases in thickness, the area of contact of the glass upon the lips increases correspondingly; and the increase of adherence and retarding friction thus created, increases the stretching action between the drawing rolls and the edge forming members, thereby counter-acting or lessening the tendency to drawing a too thick edge or border portion in the sheet.

The degree of the adherent contact of the glass upon the lips or walls of the shaping slot may thus vary, but such adherent contact is nevertheless at all times retained due to the Wedge formation of the slot.

The lips forming the slot, due to their upward extension and inclination in the direction of movement of the sheet, insures a gradual, smooth and uniform slipping action of the adherent glass which preferably is being drawn upon the upper portions of the inner surfaces of the lips. This case is a continuation in part of and an improvement over my Patent No. 1,692,585, filed Jan. 10, 1918. It is also a continuation in part of my pending application Ser. No. 702,198, filed March 27, 1924, more particularly directed to an improvement over Fig. 10 of said application'.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from, the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is 1. An apparatus for the manufacture of sheet glass, comprising a receptacle for a bath of molten glass, means for drawing sheets of glass from the bath, edge forming means positioned above the bath of glass to receive the meniscus for partially thinning the border portion and edges only, heat retaining casings extending upwardly from said edge forming means for enveloping the edges and border portions of the sheet only and retaining about such border portions and edges the heat radiating therefrom, means operative below said edge forming means for regulating the temperature conditionthereof, and means operative above said edge forming means for both regulating the temperature condition of said edge forming means and the temperature condition within said casings.

2. In apparatus for drawing glass sheets, a hot hollow stationary member open at its side and having a top and bottom slot therein through which the drawn border portion of the sheet passes, the walls of the bottom slot being hot and adhering to the initially drawn border portion of the sheet, and the walls of the upper slot being spaced from the rising border portion of the sheet being drawn therethrough. 1

3. In apparatus for drawing glass sheets, an upwardly extending heat retaining casing being open at its side to receive the border portion of the sheet, the lower portion of the casing having upwardly extending hot lip portions to form a slot adapted to contact and adhere to the rising meniscus forming the border portion of the sheet, the upperportion of the casing having converging walls to form a slot through which the rising border portion of the sheet passes.

4. In combination with a receptacle for containing a bath of molten glass, means for drawing the sheet from the free surface of the bath with the edges of the sheet taking form adjacent the walls of said receptacle, means outside said receptacle arranged in the same plane as the sheet and extending into the wall of said receptacle adjacent the source of the edge portion of the sheet for creating an anchorage at such point, and means for heating the wall of said receptacle atv the sides of such anchorage point for counter-acting the tendency to formation of abnormal areas of cooler glass adjacent the source of the drawn edge portion of the sheet.

5. An apparatus for the manufacture of sheet glass, comprising a receptacle having walls for holding a bath of molten glass from which to draw a sheet of glass, the opposed walls ofthe receptacle having pockets therein out of communication with the bath, a pocket of each of said opposed walls lying in the plane of the sheet being drawn and terminating adjacent to the source of the edges ofthe drawn sheet, means for supplying a cooling medium to said last named pockets for creating an anchorage to counteract the narrowing tendency of the sheet, the other of said pockets lying at opposite sides of said last mentioned pockets, and means for supplying a heating medium to said other of said pockets for heating the glass at opposite sides of the source of the meniscus border portion of the sheet being drawn.

6. The combination with a receptacle having walls for holding a bath of molten glass, means for drawing the sheet from the glass in said receptacle with the edges of the sheet taking form adjacent the walls of the recep tacle, edging members located above the bath adjacent said walls and engaging the forming edge portions of the sheet, air pockets in said walls opening outside the receptacle mand having closed ends adjacent the source of the drawn sheet edges, and means extending within said air-pocketsfor applying a temperature affecting medlum within the closed ends thereof adjacent the source of the drawn edges of the sheet and below said edging members.

7. In apparatus for drawing sheet glass, a shallow pot having walls for containing a bath of molten glass from which to draw edges of the sheet are drawn, and cooling means within the walls of the pot out of contact with the glass and terminating adjacent the generating edge portions of the sheet.

9. An apparatus for the manufacture of sheet glass comprising a receptacle for a bath'of molten glass, means for drawinga sheet of glass upwardly'from the bath, a hot edging member disposed above the bath of glass to contact with the rising border portion of the sheet, means for regulating the temperature of the glass bath adjacent the source of the forming sheet, a casing positioned above said edging member to receive the border portion only of the sheet, and means other than burners for regulating the temperature of the casing during drawing.

10. An apparatus for the manufacture of sheet glass comprising a receptacle for containing an open bath of molten glass, means for drawing the sheet upwardly from the open bath, a hot edging member at each forming border portion-of the sheet, said member having an open slot therein and being fixed in position wholly spaced above the bath to receive and shield the rising border portion of the sheet, the walls of the slot contacting with and adhering to said rising border portion tomaintain the desired width of the sheet, means for regulating the temperature of the glass bath beneath said hotedging member, and a slotted casing positioned above said hot edging member to receive the rising border portion of the sheet, said casing having doors for exposing the interior thereof to the outer atmosphere.

11. In apparatus for drawing sheet or plate glassirom a molten bath, a hot shielding member having diverging shielding plates forming an open ended V-shaped slot, said member being positioned wholly spaced above the surface of the bath so as to engage andadhere with the rising meniscus border only ofthe sheet, said member having an upwardly extending casing through which the rising border portion of the sheet passes, said casing further having windows ing an open slot and being disposed to resheet from the molten glass in said pot transversely thereof, edging devices for maintainceive and adherently contact to said border portions to shape said border portions; and prevent the narrowing of the sheet, said edgi'ng members further having each an upwardly extending slotted casing to receive the rising border portions of the sheet including a door to said casing for controlling the temperature of the glass passing through said edging members and casings.

13. An apparatus for .the manufacture of sheet glass comprising a receptacle for a bath of molten glass, means for drawing the sheet from the bath, a casing disposed to receivethe border portions of the sheet, said casing having a lower outer door and upper side windows to partially expose desired portions of the interior. thereof to the external atmosphere.

14. An apparatus for drawing sheetglass comprising a shallow pot for containing a bath of molten glass, means for drawing the ing the position of the edge portions of the sheet, a narrow heating chamber beneath said pot and extending in line with the source of generation of the sheet, individual heating compartments disposed at the sides of said chamber, and means for the independent local control of temperature of said chamber beneath the sheet edge producing portions of the glass.

15. An apparatus for drawing glass comprising a shallow receptacle for containing a bath of molten glass, means-for drawing the sheet from said bath, a single individual narrow temperature controlling chamber located directly beneath and in line with the entire base of the drawn sheet, andheating compartments at each side of said chamber.

16. An apparatus for drawing glass comprising a shallow receptacle for containing a bath of molten glass, means for drawing the sheet from said bath, a single individual narrow temperature controlling chamber located directly beneath and .in lineiwi th theentire base of the drawn sheet, heating compartments at each side of said chamber, and partition walls separating said chamber and compartments, said walls spaced at each side of the base of the sheet throughout the width thereof.

17. An apparatus for forming sheet glass comprising a receptacle for containing a bath of molten glass, means for drawing the sheet from the molten glass in said receptacle, and a plurality of separated individual heating and temperature controlling chambers beneath said receptacle.

18. The method of producing sheet glass which consists in drawing the sheet upwardly from an open bath of molten glass, adherently dragging the border portion of the forming sheet, at points wholly spaced above the surface of the open bath, through and against a suitable hot anchoring element to maintain the desired width of the sheet, confining the rising forming border portion of the sheet to its own heat within a suitable surrounding element, and regulating the temperature of the glass which passes through said elements by subjecting the same, in redetermined degree, to the cooling effect 0 the external atmosphere.

19. The method of producing sheet glass which consists in drawing the sheet upwardly from an open bath of molten glass, adherently dragging the thickly drawn border portions of the forming sheet, at points wholly spaced above the surface of the bath, through and against hot anchoring elements to maintain the desired width of the sheet, confining the rising border portions of the sheet within suitable surrounding elements and exposing said confined border portions, in predetermined degrees, to the cooling effect of the external atmosphere while at the same time applying heat under the bath beneath the forming border portions of the sheet to thereby regulate the temperature and adherentdragging action of the forming glass passing through said anchoring and surrounding elements.

In testimony whereof I afiix my signature.

I ARTHUR E. SPINASS-E. 

